A typical data storage system or disc drive includes a rigid housing that encloses a variety of components. The components can include a storage medium, usually in the form of one or more discs, having data surfaces for storage of digital information. The discs are mounted on a spindle motor that causes the discs to spin and the data surfaces of the discs to pass under aerodynamic bearing disc head sliders. The sliders carry transducers, which write information to and read information from the data surfaces of the discs.
To increase recording area density, fly height is lowered and the disc is manufactured as smooth as possible. During disc drive operation, serious damage to the data surface of the disc and the sliders can result during lowered fly height if a particle were to become present between the disc and the slider. In general, the majority of the storage medium defect failures are due to particle-induced scratch on the surface of the disc.
Small and large particles released from drive components and the disc drive environment are unavoidable in the disc drive. A recirculation filter is one of the filters that are currently used in disc drive filtration system to protect the disc from these particles. Existing recirculation filters are designed to trap small particles having a size at least as great as approximately 2 μm. However, particle-induced scratch can also be generated by large particles impinging on the disc at high velocities.
Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.